Dredging-machine



(No Model.)

W. B. PLESS.

DREDGING lyIAGHIm-r.`

Wit/ww Patented Apr. v29, 1890.

. UNITED STATES PATENT OFFICE.

VILLIAM B. PLESS, OF SAN FRANCISCO, ASSIGNOR OF ONE-HALF TO ROSVVELL C.SARGENT, OF SAN JOAQUIN, CALIFORNIA.

DREDGING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 426,681, dated April29, 1890.

Application filed November 18, 1889. Serial No. 330,687. (No model.)

To all whom it may concern.-

Be it known that I,WILLIAM B. PLESS, a citizen of the United States,residing at San Francisco, in the county of San Francisco and State ofCalifornia, have invented certain new and useful Improvements inDredging- Machines; and I do declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanyiug drawings, and to the letters ofreference marked thereon, which form a part of this specification.

My invention relates to that class of dredging-machines which arelocated on a iioating vessel, the same to be used in connection with myinvention set forth in application for Letters Patent, Serial N o.305,269, for an improvement in derricks for dredging-machines, whichapplication was allowed on the 22d day of July, 1889, andv the noveltywill be fully understood from the following description, when taken inconnection with the accompanying drawings, in which` Figure l is a sideelevation of my complete dredging-machine and its vessel. Fig. 2 is aside elevation of the dipper, showing in dotted line the position of theparts when open.

In order to better illustrate and render my improvements more easy ofcomprehension, I shall describe specifically a portion of a vessel towhich said improvements are to be at'- tached, together with themachinery for operating the same.

In said drawings, to which letters of reference are made, A B representthe hull of the vessel, upon which are located the operating devices andmachinery.

.'o in jaws J, secured to the foot of the mast G.

A large iron block E, having an eye, is also ing to the engineY or othermotive power within the hull. Forwardly-extending jaws I-I are attachedto the turn-table and embrace the boom J.

I shall now give a detailed description of the construction andoperation of my improvements as employed in connection with the vesseland its operating mechanism.

N N are the jaws of the dipper, which is of a clam-shell pattern. a andb are the handles, to which are attached lever-arms c, having eyes attheir outer ends. The handles c and b are pivoted at a working centerupon a shaft el. The dipper is suspended by chains M attached theretoand to a pulley M, and by chains L, attachedto the eyes of the arm c andto a pulley L.

A hoisting-chain K is attached at the outer end of the boom J, passesthrough the pulley L, over a sheave at J 3 in boom J, also over a sheaveat G in the mast G, then extends downward inside of the mast G, over asheave G3 at the bottom of the beam C, and is suitably connected to themotive power within the hull. A chain K is likewise attached to theouter end of the boom J and passes through the pulley M and upward overa sheave at J 3, and extends rearwardly and downward over sheaves at Gand G3 to the motive power. When both the chains K and K are wound upand the dipper is pendent, both chains may be slacked at once and thedipper lowered.

Vhen the dipper is upon the mud, chain K may be wound up, causing thejaws of the dipper to close and take its load, which having taken placeit is elevated. When the desired elevated position has been reached, thederrick, by means of the turn-table mechanism, is swung around to thedesired point of delivery, the chain K is slacked, the jaws of IOC theclipper open, its load is discharged, the derrick is swung back, thechain K is slftcked, the jaws of the dipper close, and it descends foranother load.

5 Having thus fully described my invention,

what I claim is- In combination with the swinging derriek constructedsubstantially as described, the hoisting and operating chains K and K',the

Io pulleys L M, and the Chun-shell dipperN, suitably suspended from thepulleys L and M, provided with the handles b, having the leverfirms oattached thereto, LS set forth.

In testimony whereof I iix my signature in presence of two Witnesses.

WILLIAM B. PLESS. Witnesses:

JOSHUA B. WEBSTER, JAS. T. SUMMERVILLE.

